Answer:
58.32
Explanation:
The mass number is one mole and for Mg it is 24.306 for O it is 15.999 and for H it is 1.008. because O and H have 2, you multiply them by 2 and add all the numbers and it equals 58.32
An atom is the smallest part of an element
Answer:
4 significant digits
Explanation:
Zeroes placed between other digits are always significant
Answer is: volume of helium is 244.72 liters.
m(He) = 43.7 g.
n(He) = m(He) ÷ M(He).
n(He) = 43.7 g ÷ 4 g/mol.
n(He) = 10.925 mol.
V(He) = n(He) · n(He).
V(He) = 10.925 mol · 22.4 L/mol.
V(He) = 244.72 L.
Vm - molar volume at STP.
n - amount of substance.
Answer: The number of N atoms in 137.0 g of N2O3 21.67 x 10∧23 atoms.
Explanation:
- We must obtain the number of moles of the compound: (n = mass/molar mass), mass = 137.0 g and molar mass of N2O3 = 76.01 g/mol.
- n = (137.0 g)/ (76.01 g/mol) = 1.80 mol.
- It is necessary to determine the number of molecules of this sample.
- Every mole contains Avagadro's number (6.02 x 10^23) of molecules.
- The number of molecules = (6.02 x 10^23)(1.80) = 10.84 x 10∧23 molecules.
- Every molecule of N2O3 contain 2 atoms of N.
- The number of N atoms in 137.0 g of N2O3 = (10.84 x 10∧23 molecule) (2 atoms) = 21.67 x 10∧23 atoms.
